Homemade Liquid Castile Soap

Castile soap finds its origins in Castile, Spain, where it was made of olive oil and animal fat. Today's castile soap retains these natural roots, relying only on plant oils and an alkali ingredient -- sodium hydroxide or potassium hydroxide -- to create a gentle, biodegradable and eco-friendly soap. Commercially produced castile soap, however, tends to come at a higher price than other off-the-shelf options. Make your own castile soap bars, then break them down into liquid form for convenient hand-washing.

Things You'll Need

Rubber gloves

Face mask

Safety goggles

Distilled water

Mixing bowl

Measuring scale

Lye crystals, or sodium hydroxide

Spatula

Stainless steel pot

Pomace-grade extra virgin olive oil

Kitchen thermometer

Electric hand mixer

Soap mold

Wax paper

Cardboard

Towel

Kitchen knife

Vegetable grater

Funnel

Soap dispenser bottle

Make the Bars

Put on rubber gloves, safety goggles and a face mask.

Pour 10 ounces of distilled water into a mixing bowl. Measure out 4.33 ounces of lye crystals and gently stir them into the water with a spatula until they dissolve completely. Wait as the water becomes hot, then set the mixture aside and allow it to cool.

Heat 34 ounces of Pomace-grade, extra-virgin olive oil in a stainless steel pot over low to medium heat. Use a thermometer to keep track of the oil's temperature; when the temperature reaches 100 degrees Fahrenheit, cut the heat. As the oil heats, check the temperature of the water-lye mixture; it should cool down to about 100 degrees as well.

When both the oil and water-lye solution reach 100 degrees, drizzle the lye solution into the oil and stir it with an electric hand mixer. Mix until it takes on a gooey texture, known as the trace stage.

Line a soap mold with wax paper, then slowly and evenly pour the soap mixture into the mold. Place a piece of cardboard over the trays and a towel on top of the cardboard, then allow the soap to rest for 48 hours.

Remove the hardened soap from the mold and carefully cut it into bars with a sharp kitchen knife. Place the soap on a sheet of wax paper and allow it to cure for at least two weeks. After two weeks, the soap is ready to use or liquefy.

Liquefy the Soap

Cut one average-sized bar of the homemade castile soap into smaller, more manageable chunks. Using a vegetable grater, grate the soap into a pot of boiling water. Use about 8 cups of distilled or filtered water per bar.